Why doesn't this script extrude the cone base in edit mode?
A Command, select_face_by_sides, can be used.
However, this does not work when the bottom face is a triangle.

import bpy

bpy.ops.mesh.primitive_cone_add(location=(0,0,0))
bpy.ops.transform.translate(value=(0, 0, 1.94102), constraint_axis=(False, False, True), constraint_orientation='GLOBAL', mirror=False, proportional='DISABLED', proportional_edit_falloff='SMOOTH', proportional_size=1, release_confirm=True)
bpy.ops.object.editmode_toggle()

bpy.ops.mesh.select_face_by_sides(
        number=3, 
        type='GREATER', 
        extend=False
    )

bpy.ops.mesh.extrude_region_move(MESH_OT_extrude_region={"mirror":False}, TRANSFORM_OT_translate={"value":(-1.97143e-009, 3.68831e-009, 0.447236), "constraint_axis":(False, False, True), "constraint_orientation":'NORMAL', "mirror":False, "proportional":'DISABLED', "proportional_edit_falloff":'SMOOTH', "proportional_size":1, "snap":False, "snap_target":'CLOSEST', "snap_point":(0, 0, 0), "snap_align":False, "snap_normal":(0, 0, 0), "gpencil_strokes":False, "texture_space":False, "remove_on_cancel":False, "release_confirm":False})